gecko-dev/layout/svg/nsCSSFilterInstance.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef __NS_CSSFILTERINSTANCE_H__
#define __NS_CSSFILTERINSTANCE_H__
#include "FilterSupport.h"
#include "gfxMatrix.h"
#include "gfxRect.h"
#include "mozilla/gfx/Point.h"
#include "mozilla/gfx/Types.h"
#include "nsColor.h"
#include "mozilla/ServoStyleConsts.h"
/**
* This class helps nsFilterInstance build its filter graph. It turns a CSS
* filter function (e.g. blur(3px)) from the style system into a
* FilterPrimitiveDescription connected to the filter graph.
*/
class nsCSSFilterInstance {
using StyleFilter = mozilla::StyleFilter;
typedef mozilla::gfx::sRGBColor sRGBColor;
typedef mozilla::gfx::FilterPrimitiveDescription FilterPrimitiveDescription;
typedef mozilla::gfx::IntPoint IntPoint;
typedef mozilla::gfx::Size Size;
public:
/**
* @param aFilter The CSS filter from the style system. This class stores
* aFilter by reference, so callers should avoid modifying or deleting
* aFilter during the lifetime of nsCSSFilterInstance.
* @param aShadowFallbackColor The color that should be used for
* drop-shadow() filters that don't specify a shadow color.
* @param aTargetBoundsInFilterSpace The pre-filter visual overflow rect of
* the frame being filtered, in filter space.
* @param aFrameSpaceInCSSPxToFilterSpaceTransform The transformation from
* the filtered element's frame space in CSS pixels to filter space.
*/
nsCSSFilterInstance(
const StyleFilter& aFilter, nscolor aShadowFallbackColor,
const nsIntRect& aTargetBoundsInFilterSpace,
const gfxMatrix& aFrameSpaceInCSSPxToFilterSpaceTransform);
/**
* Creates at least one new FilterPrimitiveDescription based on the filter
* from the style system. Appends the new FilterPrimitiveDescription(s) to the
* aPrimitiveDescrs list.
* aInputIsTainted describes whether the input to this filter is tainted, i.e.
* whether it contains security-sensitive content. This is needed to propagate
* taintedness to the FilterPrimitive that take tainted inputs. Something
* being tainted means that it contains security sensitive content. The input
* to this filter is the previous filter's output, i.e. the last element in
* aPrimitiveDescrs, or the SourceGraphic input if this is the first filter in
* the filter chain.
*/
nsresult BuildPrimitives(
nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
bool aInputIsTainted);
private:
/**
* Returns a new FilterPrimitiveDescription with its basic properties set up.
* See the comment above BuildPrimitives for the meaning of aInputIsTainted.
*/
FilterPrimitiveDescription CreatePrimitiveDescription(
const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
bool aInputIsTainted);
/**
* Sets aDescr's attributes using the style info in mFilter.
*/
nsresult SetAttributesForBlur(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForBrightness(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForContrast(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForDropShadow(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForGrayscale(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForHueRotate(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForInvert(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForOpacity(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForSaturate(FilterPrimitiveDescription& aDescr);
nsresult SetAttributesForSepia(FilterPrimitiveDescription& aDescr);
/**
* Returns the index of the last result in the aPrimitiveDescrs, which we'll
* use as the input to this CSS filter.
*/
int32_t GetLastResultIndex(
const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs);
/**
* Sets aDescr's filter region and primitive subregion to appropriate values
* based on this CSS filter's input and its attributes. For example, a CSS
* blur filter will have bounds equal to its input bounds, inflated by the
* blur extents.
*/
void SetBounds(FilterPrimitiveDescription& aDescr,
const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs);
/**
* Converts an nscolor to a Color, suitable for use as a
* FilterPrimitiveDescription attribute.
*/
sRGBColor ToAttributeColor(nscolor aColor);
/**
* Converts a blur radius in frame space to filter space.
*/
Size BlurRadiusToFilterSpace(nscoord aRadiusInFrameSpace);
/**
* Converts a point defined by a pair of nscoord x, y coordinates from frame
* space to filter space.
*/
IntPoint OffsetToFilterSpace(nscoord aXOffsetInFrameSpace,
nscoord aYOffsetInFrameSpace);
/**
* The CSS filter originally from the style system.
*/
const StyleFilter& mFilter;
/**
* The color that should be used for drop-shadow() filters that don't
* specify a shadow color.
*/
nscolor mShadowFallbackColor;
/**
* The pre-filter overflow rect of the frame being filtered, in filter space.
* Used for input bounds if this CSS filter is the first in the filter chain.
*/
nsIntRect mTargetBoundsInFilterSpace;
/**
* The transformation from the filtered element's frame space in CSS pixels to
* filter space. Used to transform style values to filter space.
*/
gfxMatrix mFrameSpaceInCSSPxToFilterSpaceTransform;
};
#endif